It seems that all of my chargers won't put a charge to a full on dead battery.  And I'm having trouble finding a small reliable charger that will.

Does anyone have a rock solid recommendation?

The best maintenance battery charger is Battery Tender.

It cannot bring a battery back from the dead. No charger can do that!

USA Battery Chargers make from large roll around shop units to small portable units. Once of the important features when battery tending is the ability to go to complete zero off and then back on as needed. These chargers are USA made and have worked very well for us. (Military applications)

http://www.usabatterychargers.com/126AC.htm

A bunch of guys over at steelsoldiers as well as myself use a NOCO Genius G7200 for our 12-24v batteries. It has a smart charge, and does agm batteries like optimas, and it has a restore feature which does help bring a battery back to life.

usually 90-100 bucks online and amazon. good luck

I've got a Schumacher automatic smart charger with the 100 amp boost for starting "assist".
It will do AGM and I think gel cells too. It has a desulphate function also.


It can be had at Northern Tools for $90.00 right now

Actually you don't need a new battery charger - you need an old one.

All the super duper automatic chargers these days have circuitry that test batteries and if they see certain conditions - like really low voltage - the protection mode kicks in and they refuse to charge.  My favorite Schumacher SCC-1000A actually says "bad bat" in it's primitive 3 character LED display.  Which is actually a pretty good safety feature, because if you left a defective battery charging unattended you may come back to find it burst and sprayed sulfuric acid all over your garage or even that the vented hydrogen gas had ignited.

Which is exactly why I retired my old Harbor Freight charger.  It weighed like 20 lbs. and was nothing more than a big transformer and rectifier with some sort of semi-effective current limiting device.  You hooked it up to a battery and it would force current through it regardless of whether it was totally dead, sulfated, had shorted cells, etc.  It didn't care - it just turned on the juice went to town.  And after cooking a few expensive batteries I decided to get something that was a little smarter.

But in the OP's case, he definitely needs a dumb charger.  The dumber the better.  When the GF left her dome light on all weekend and ran battery voltage down to zero, my Schumacher refused to charge it.  So I hooked up the stupid HF charger for a few minutes force charging it at 10 amps and it brought the voltage up enough where the Schumacher would then start it's automatic charging cycle.  That was all it took to bring the dead battery up into the range where the smart charger liked it enough to give it a try.

If you don't have an old brute force charger, you can try just hooking it up to another battery with jumper cables.  Again, only for a few minutes, and don't leave it unattended.  Any weird bubbling or hissing noises, or visible vapors and you should disconnect it.

Any time you run a standard battery down to zero you've caused some damage and should consider replacing it.  But at least by giving it a little blast charge to jump start the recharging cycle means you won't have to do it today.

Yeah I have all the bases covered for hi-tech pulsing chargers... the old style is what I'm after. Sometimes its the only thing to restart a battery that's completely dead.

2 things, be aware battery tender warranty is crap. you pay shipping both ways when they crap out.

had 2 fail and don't use them anymore.

ctek or shumaker are the only 2 I use now.

2nd, you can fool the new chargers if you have a second battery you can wire in parellel. it will then see a charge it can work with.